CN213977502U - Continuous production device of hydroxyl acrylic resin - Google Patents

Abstract

The application provides a continuous production device of hydroxyl acrylic resin. The continuous production device comprises a mixing unit, a material conveying system, a polymerization reaction unit, a receiving unit and a heat exchange system. The mixing unit comprises a plurality of mixers capable of premixing materials. The material conveying system comprises a plurality of feeding pumps which provide power for continuous conveying of materials, and a mixed liquid inlet of the material conveying system is communicated with a mixed liquid outlet of the mixing unit. The polymerization reaction unit can receive the material through mixing and react and generate hydroxyl acrylic resin, and the polymerization reaction unit includes mixed liquid import and resin outlet, and the mixed liquid import of polymerization reaction unit communicates in material conveying system's mixed liquid export. The receiving unit is used for receiving hydroxyl acrylic resin and comprises a resin inlet, and the resin inlet of the receiving unit is communicated with the resin outlet of the polymerization reaction unit. The heat exchange system comprises a material heat exchange system and a reaction temperature control system.

Description

Continuous production device of hydroxyl acrylic resin

Technical Field

The application relates to a production device of hydroxyl acrylic resin, in particular to a continuous production device of hydroxyl acrylic resin.

Background

The hydroxyl acrylic resin has the properties of high hardness, high gloss, high fullness, excellent adhesion, leveling property, toughness, weather resistance, corrosion resistance, quick drying and the like after being acted by an isocyanate curing agent, can be used for preparing PU (polyurethane) two-component paint, automobile refinishing paint, wood furniture polyester paint, mechanical finish paint, high gloss finish paint, finishing paint, varnish, colored paint and the like, and is widely applied to the fields of automobiles, machinery, furniture and the like.

Many studies on the synthesis of hydroxy acrylic resins are limited to slowly dropping (monomers, solvents, initiators, etc.) at a lower reaction temperature and then keeping the temperature for a longer time. The quality of the hydroxyl acrylic resin directly obtained in the way is often poor, and the product needs to be filtered before being packaged. The preparation method of the hydroxy acrylic resin disclosed in CN104231148A comprises the following steps: adding a part of solvent in advance into a reaction kettle, heating to a reflux temperature, dropwise adding a mixture of a first part of monomer, a chain transfer agent and an initiator at a temperature of not higher than 130 ℃ for 2-5 h, then preserving heat for 1-2 h, dropwise adding the rest initiator and the solvent for 0.5-1 h, continuing preserving heat for reaction for 2-4 h, and finally cooling to below 70 ℃ and filtering to obtain the hydroxyl acrylic resin. The preparation method of the hydroxy acrylic resin disclosed in CN102766263B comprises the following steps: the method comprises the steps of adding a mixture with a solvent as a main component into a reaction kettle in advance, dropwise adding a monomer and a catalyst for 3-4 hours at a reaction temperature of 105-115 ℃, then preserving heat for 0.5-2 hours at a temperature of 100-120 ℃, heating to 115-125 ℃, dropwise adding the catalyst, then preserving heat for 4.5-6.5 hours, dropwise adding a mixed solution containing the solvent, preserving heat for 1.5-2.5 hours, and finally cooling to a temperature below 75 ℃ and filtering to obtain the hydroxyl acrylic resin.

Raising the reaction temperature to some extent is advantageous in reducing the molecular weight of the polymer and reducing the viscosity of the resin to obtain a hydroxy acrylic resin having a higher solid content, and the reaction time can be shortened. However, although the reaction time can be shortened by raising the reaction temperature, the dropping speed can be controlled to prolong the dropping time in order to avoid the reaction out of control. CN106084143B discloses a preparation process of a low VOC (volatile organic compound) hydroxyacrylic acid resin, which comprises: adding a part of mixed solution containing a solvent into a high-pressure reaction kettle in advance, heating to 150-170 ℃, controlling the pressure to be 0.1-0.3 MPa, stabilizing for 10-30 min, dropwise adding the mixed solution of a monomer and an initiator for 3-6 h, dropwise adding a mixture of the initiator and the solvent twice, respectively keeping the temperature for 30-90 min and 3-5 h after dropwise adding, and finally cooling to below 70 ℃ and filtering to obtain the hydroxyl acrylic resin. Although the high-pressure reaction kettle can be used for obtaining the hydroxyl acrylic resin with higher solid content at higher temperature, the high-temperature and high-pressure operation is high in danger and the reaction is not easy to control due to the larger volume of the reaction kettle in the production process, and the obtained hydroxyl acrylic resin is often required to be filtered. The preparation method of the high-solid low-viscosity hydroxy acrylic resin disclosed by CN106009454B comprises the following steps: adding a part of solvent and monoglycidyl ether into a reaction kettle in advance, stirring and heating to 140-180 ℃, dropwise adding a mixture of an initiator, a chain transfer agent and a monomer for 3-6 h, then preserving heat for 0.5-1 h, dropwise adding the rest of the initiator and the solvent for 20-40 min, and continuously preserving heat for reacting for 1-2 h to obtain the hydroxyl acrylic resin, but adding more substances with stronger hydrophilicity and reduced viscosity, such as monoglycidyl ether, vinyl versatate and hydroxyl oligomer, into the formula in order to improve the solid content of the resin, so that the cost of resin raw materials is increased although the obtained hydroxyl acrylic resin achieves the effects of high solid content and low viscosity, and the paint film of the paint prepared by using the resin has poor corrosion resistance and water resistance.

Although the reaction temperature is continuously improved in the research of the synthetic method of the hydroxyl acrylic resin, the temperature and the time of the dropping reaction and the heat preservation reaction are adjusted, the highest reaction temperature does not exceed 180 ℃, the time of the dropping reaction and the heat preservation reaction is longer as a whole, and a large amplification effect exists from small-scale experiments to large-scale industrialization. Therefore, the batch kettle type process has the problems of complicated operation process, low production efficiency and poor safety.

SUMMERY OF THE UTILITY MODEL

The application provides a continuous production device of hydroxyl acrylic resin.

The continuous production device of the hydroxyl acrylic resin comprises:

the mixing unit comprises a plurality of blenders capable of premixing materials, and comprises a material inlet and a mixed liquid outlet;

the material conveying system comprises a plurality of feeding pumps which provide power for the continuous conveying of materials, the material conveying system comprises a mixed liquid inlet and a mixed liquid outlet, and the mixed liquid inlet of the material conveying system is communicated with the mixed liquid outlet of the material mixing unit;

the polymerization reaction unit can receive the mixed materials and react to generate hydroxyl acrylic resin, the polymerization reaction unit comprises a mixed liquid inlet and a resin outlet, and the mixed liquid inlet of the polymerization reaction unit is communicated with the mixed liquid outlet of the material conveying system;

the receiving unit is used for receiving hydroxyl acrylic resin and comprises a resin inlet, and the resin inlet of the receiving unit is communicated with the resin outlet of the polymerization reaction unit; and

the heat exchange system comprises a material heat exchange system and a reaction temperature control system.

In at least one embodiment, the upper pressure limit of the feed pump of the material delivery system is not less than 2 MPa.

In at least one embodiment, the polymerization reaction unit comprises a continuous channel reactor,

the continuous channel reactor comprises a micro-channel reactor and a tubular reactor,

the microchannel reactor has a mixing function,

the tubular reactor comprises one or more of a static mixer with a mixing unit in the lumen, a static tubular reactor without a mixing unit in the lumen, and a dynamic tubular reactor with moving parts in the lumen.

In at least one embodiment, the mixing unit comprises two mixed liquor outlets, and the two mixed liquor outlets are communicated with a microchannel reactor or a static mixer or a dynamic tube reactor at the front end of the continuous channel reactor.

In at least one embodiment, the mixing unit includes three mixed liquor outlets,

the two mixed liquid outlets of the mixing unit are communicated with a micro-channel reactor or a static mixer or a dynamic tubular reactor which is positioned at the front end of the continuous channel reactor,

the other mixed liquid outlet of the mixing unit is communicated with a micro-channel reactor or a static mixer or a dynamic tubular reactor in the continuous channel reactor,

the resin outlet of the polymerization reaction unit is positioned on the tubular reactor at the rear end of the continuous channel reactor.

In at least one embodiment, the heat exchange system comprises a reaction temperature control system, and the polymerization reaction unit forms at least one temperature zone through the reaction temperature control system.

In at least one embodiment, the material heat exchange system can preheat mixed liquid after materials are mixed and can cool the hydroxy acrylic resin produced by the polymerization reaction unit,

the material heat exchange system comprises a first material heat exchange system and a second material heat exchange system,

the first material heat exchange system comprises a hot resin inlet, a first-stage cooled resin outlet, a first mixed liquid inlet and a preheated first mixed liquid outlet;

and the second material heat exchange system comprises a first-stage cooled resin inlet, a second-stage cooled resin outlet, a second mixed liquid inlet and a preheated second mixed liquid outlet.

In at least one embodiment, the continuous production apparatus comprises a backpressure-regulating device,

the back pressure adjusting device comprises a pressure adjusting valve and a pressure sensor which are arranged between a second-stage cooled resin outlet of the second material heat exchange system and a resin inlet of the receiving unit,

the backpressure of the polymerization reaction unit and the backpressure of the heat exchange system are controlled to be 1-5 MPa.

In at least one embodiment, the continuous production plant comprises an overpressure safety interlock system comprising a pressure sensor and a flow sensor arranged in the material conveying system, and/or

The continuous production apparatus includes an over-temperature safety interlock system including a temperature sensor disposed in the polymerization reaction unit.

In at least one embodiment, the mixer in the mixing unit is a stirred tank, and the heat exchange device of the heat exchange system is a dividing wall type heat exchanger.

In order to solve the problems in the prior art, the application provides a continuous production device for hydroxyl acrylic resin, which can obtain the hydroxyl acrylic resin by adopting a high-temperature method, and has the advantages of short time consumption, high production efficiency and high safety.

Drawings

Fig. 1 shows a schematic diagram of a continuous production plant for hydroxyacrylic resins according to an embodiment of the present application comprising two material inlets.

Fig. 2 shows a schematic diagram of a continuous production plant for hydroxyacrylic resins according to an embodiment of the present application comprising three material inlets.

Description of the reference numerals

1, a mixing unit; 1-1 a first mixer; 1-2 second mixer; 1-3 a third mixer;

2, a material conveying system; 3 a polymerization reaction unit; 4 a receiving unit; 5, a reaction temperature control system;

6-1, a first material heat exchange system; 6-2 second material heat exchange system.

Detailed Description

Exemplary embodiments of the present application are described below with reference to the accompanying drawings. It should be understood that the detailed description is only intended to teach one skilled in the art how to practice the present application, and is not intended to be exhaustive or to limit the scope of the application.

The present application provides a continuous production apparatus (hereinafter, sometimes simply referred to as "continuous production apparatus") for a hydroxyacrylic resin, as shown in fig. 1, the continuous production apparatus comprising a mixing unit 1, a material conveying system 2, a polymerization reaction unit 3, a receiving unit 4, and a heat exchange system. The solid content of the hydroxyl acrylic resin obtained by the continuous production device can be 50-90%.

In at least one embodiment, the mixed liquor outlet of the mixing unit 1 is connected to the mixed liquor inlet of the material conveying system 2, the mixed liquor outlet of the material conveying system 2 is connected to the mixed liquor inlet of the polymerization reaction unit 3, and the resin outlet of the polymerization reaction unit 3 is connected to the resin inlet of the receiving unit 4.

In this application, it should be noted that, unless explicitly stated or limited, the connection (communication) between the systems and units should be understood in a broad sense, for example, direct pipe connection, pipe connection with pipe valves, indirect connection via intermediate media, fixed connection, or detachable connection. The specific meaning of the above terms in the present application can be understood by those skilled in the art as appropriate.

In the present application, the mixing unit 1 is used for premixing materials which do not react with each other at normal temperature, and conveying the materials to a polymerization unit 3 (described later) through a material conveying system 2 (described later). The materials which do not react in advance are mixed and then conveyed, so that the condition that each material is conveyed by one pump is avoided, the number of feeding pumps can be reduced, and the purpose of saving the input cost of equipment is achieved.

As shown in fig. 1, in one embodiment of the present application, the mixing unit 1 may include a first mixer 1-1 and a second mixer 1-2, and the first mixer 1-1 and the second mixer 1-2 are used to mix the first mixed liquid and the second mixed liquid, respectively. The first mixed solution may include the monomer and the solvent (it is understood that the monomer in the first mixed solution may include all or only a portion of the monomer) or only the monomer. The second mixed solution may contain an initiator or an initiator and a solvent, or an initiator and a monomer, or an initiator, a solvent and a monomer. The first mixer 1-1 and the second mixer 1-2 are preferably stirred tanks.

As shown in fig. 2, in one embodiment of the present application, the mixing unit 1 further comprises a third mixer 1-3, the third mixer 1-3 is used for mixing a third mixed solution, the third mixed solution may contain a solvent, an initiator or a monomer, a solvent, an initiator or only an initiator, and the third mixer 1-3 is preferably a stirred tank.

The third mixer 1-3 is used for premixing the third mixed liquid, and the third mixed liquid is used for distinguishing the first mixed liquid from the second mixed liquid, so that the materials are conveyed to the polymerization reaction unit 3 in a segmented manner, the conversion rate of monomers is improved, the viscosity of resin is reduced, the concentrated reaction heat release is avoided to a certain extent, and the workload of a reaction temperature control system 5 (described later) is reduced.

The monomer may include a hydroxyl monomer, a carboxyl monomer, a hard monomer, a soft monomer. The hydroxyl monomer can be one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and hydroxybutyl acrylate. The carboxyl monomer may include at least one of acrylic acid and methacrylic acid. The hard monomer can be one or more of styrene, methyl acrylate, methyl methacrylate, ethyl methacrylate and isobornyl acrylate. The soft monomer can be one or more of ethyl acrylate, isooctyl methacrylate, butyl acrylate, butyl methacrylate and lauryl acrylate. Wherein the mass of the hydroxyl monomer can account for 12-40% of the total monomer mass, the mass of the carboxyl monomer can account for 0.1-3.8% of the total monomer mass, and the mass of the hard monomer and the soft monomer can both account for 20-60% of the total monomer mass.

In the application, the mass of the hydroxyl monomer can account for 12-40% of the total mass of the monomers, the hydroxyl value of the hydroxyl acrylic acid aqueous dispersion can be ensured to be 60-155 mgKOH/g, and the adhesive force, wetting dispersibility, chemical properties and mechanical properties of a paint film are good in the range. The condition that a space network structure is not easily formed due to the fact that blocking chain breakage occurs when the hydroxyl acrylic resin and the curing agent are crosslinked because the hydroxyl monomers are too few is prevented; and preventing the hydroxyl monomer from being excessive, improving the crosslinking density of the group, making the contact of the hydroxyl group with isocyanate difficult, and remaining hydroxyl groups in the system to reduce the water resistance of the paint film and increase the cost of the curing agent.

In the application, the mass of the carboxyl monomer accounts for 0.1-3.8% of the total mass of the monomers, so that the acid value of the corresponding hydroxy acrylic resin is 1-25 mgKOH/g, and the conditions that the carboxyl monomer is used in too low amount, and the adhesive force and the wetting dispersibility of a paint film are poor are prevented; and the conditions that the use amount of the carboxyl monomer is too high, the hydrophilicity of the resin is increased, and the water resistance and the storage stability of a paint film are reduced are prevented.

The solvent adopted in the application can be one or more of propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol butyl ether, propylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, toluene, xylene, No. 100 solvent oil, butyl acetate, isobutyl acetate, n-butyl alcohol and isobutyl alcohol. For the production of the hydroxy acrylic resin with high solid content for preparing the hydroxy acrylic resin aqueous dispersion, solvents with low boiling point and hydrophilicity and lipophilicity are preferred, such as propylene glycol methyl ether, propylene glycol ethyl ether and propylene glycol monomethyl ether acetate, so as to avoid the problem that the residual time is too long due to too slow volatilization of the solvents in the product application process, and the product application is influenced; toluene, xylene and butyl acetate with better compatibility are preferably selected for the solvent type hydroxy acrylic resin.

The initiator adopted by the method can be at least one of di-tert-butyl peroxide, di-tert-amyl peroxide, diisopropyl peroxide, tert-butyl peroxyacetate, tert-butyl cumyl peroxide and di-tert-butyl diisopropylbenzene peroxide, the decomposition temperature is 160-200 ℃ when the half-life period is 1min, and the purpose is that the initiator can be rapidly decomposed to generate free radicals at the reaction temperature, the chain initiation process is shortened, and the polymeric molecules with shorter molecular chains are obtained.

In at least one embodiment, the mass ratio of the monomer to the solvent in the first mixed solution may be 45-89: 0-20, and the mass ratio of the initiator to the solvent and the monomer in the second mixed solution may be 1-5: 0-30: 0 to 20. The mass ratio of the monomer, the solvent and the initiator can be 45-89: 10-50: 1-5.

In the present application, the material conveying system 2 serves to achieve a continuous conveyance of material. Because the material can generate certain resistance in the flowing process, certain pressure drop can be generated; in addition, because the temperature in the reaction process is higher than the boiling point of the solvent and part of the monomers, a certain pressure needs to be provided in order to prevent the materials from vaporizing. Therefore, in order to achieve the entrance of the materials into the polymerization reaction unit 3 and the receiving unit 4, the material conveying system 2 preferably includes at least two feed pumps having a pressure-resistant range, and the upper pressure-resistant limit of the feed pumps is not lower than 2 MPa. So as to prevent the situation that when the upper limit of the pressure resistance of the feeding pump is lower than 2MPa, the power provided in the process of conveying materials is limited, so that the products cannot smoothly enter the receiving unit 4, or the feeding is stopped because the pressure of the whole continuous production device is higher than the upper limit of the pressure of the feeding pump.

The conventional batch kettle type reaction mostly adopts the method that a solvent is added into a reaction kettle in advance and preheated to a certain temperature, and then the monomer and the initiator are dripped for many times, and in order to ensure the controllable reaction and the product quality, a starvation method for reducing the dripping speed is adopted, so that the initiator with higher concentration is always kept in the monomer. However, in order to realize mass production, the reaction kettle adopted in general industrial production has a large volume, and although the stirring form is continuously improved, the phenomena of uneven mixing and severe back mixing always exist in the reaction kettle, which easily causes the phenomena of large difference of the polymerization degree of the resin, wide molecular weight distribution, and large viscosity and poor quality of the finally obtained resin product.

According to the application, for the synthesis of hydroxyl acrylic resin, a large number of experimental researches show that a process of forced mass transfer can be set between a polymerization monomer and an initiator in the early stage of reaction, so that the purpose that free radicals generated by rapid decomposition of the initiator can be uniformly contacted with the monomer at high temperature is ensured, the monomer is uniformly subjected to polymerization reaction in the process of flowing in a reaction channel, a molecular chain with concentrated molecular weight is formed, and the branching degree is reduced.

In the application, the heat exchange system comprises a material heat exchange system and a reaction temperature control system 5, the material heat exchange system comprises a first material heat exchange system 6-1 and a second material heat exchange system 6-2, the first material heat exchange system 6-1 is used for achieving first-stage cooling of the hydroxyl acrylic resin and preheating of a first mixed solution, and the second material heat exchange system 6-2 is used for achieving second-stage cooling of the hydroxyl acrylic resin and preheating of a second mixed solution.

In the present application, the polymerization reaction unit 3 may be a continuous channel reactor, which may take the form of any combination of a microchannel reactor and a tubular reactor. Increasing the reaction temperature, according to common knowledge of those skilled in the art, can accelerate the decomposition of the initiator, thereby increasing the rate at which the monomers undergo polymerization and shortening the molecular weight of the polymerized molecules. Therefore, by virtue of the excellent heat exchange effect of the continuous channel reactor, the reaction temperature can be increased, high-temperature reaction is realized, the retention time of materials in the reactor is shortened, and the quality of resin is improved.

The tubular reactor can be a static tubular reactor and/or a dynamic tubular reactor, the static tubular reactor can comprise a static tubular reactor (also called static mixer) with a mixing unit in a tubular cavity and a static tubular reactor without a mixing unit in the tubular cavity, and the dynamic tubular reactor is a tubular reactor with a moving part in the tubular cavity.

In embodiments of the present application, the combination of a continuous channel reactor may be: the microchannel reactor and the static tubular reactor are sequentially connected in series; the microchannel reactor and the static mixer are sequentially connected in series; the microchannel reactor and the dynamic tubular reactor are sequentially connected in series; the static mixer and the static tubular reactor are sequentially connected in series; the dynamic tubular reactor and the static tubular reactor are sequentially connected in series; the microchannel reactor, the first static tubular reactor, the static mixer and the second static tubular reactor are sequentially connected in series; or the microchannel reactor, the first static tubular reactor, the dynamic tubular reactor and the second static tubular reactor are sequentially connected in series, and the like.

The application can adopt a micro-channel reactor or a static mixer or a dynamic tubular reactor with a mixing function as a front-end reactor of the continuous channel reactor, so that mixed liquor can be quickly and uniformly mixed and reacted after entering the front-end reactor of the continuous channel reactor. The microchannel reactor or the static mixer is preferably used as a front-end reactor of the continuous channel reactor, and the microchannel reactor is more preferably used as a front-end reactor of the continuous channel reactor. In order to realize industrial mass production of the hydroxyacrylic resin and to reduce the equipment investment cost, a tubular reactor is preferable as the rear end reactor of the continuous channel reactor. The mixed liquid inlet of the polymerization reaction unit 3 may be located on the front-end reactor of the continuous channel reactor, and the resin outlet of the polymerization reaction unit 3 may be located on the rear-end reactor of the continuous channel reactor.

In one embodiment of the present application, the inlet for the third mixed liquor may be located on a microchannel reactor with mixing function or a static mixer or a dynamic tube reactor in a continuous channel reactor.

Both microchannel reactors and tubular reactors referred to in this application are commercially available. According to the general knowledge of those skilled in the art, the continuous channel reactor has excellent mass and heat transfer effects, and has been practically used in the chemical production field, and in the present application, the exothermic amount during the reaction and the effective volume of the reactor can be calculated by simulation calculation according to the yield of the hydroxy acrylic resin, so that a suitable reactor can be selected on the market.

Through a large amount of experimental researches, the application discovers that the hydroxy acrylic resin with low polymerization degree and concentrated molecular weight distribution can be obtained in a short reaction time under the condition of high-temperature reaction by adopting a continuous production mode. The reaction temperature adopted by the method is 160-230 ℃. If the reaction temperature is too low, the retention time of the materials in the continuous channel reactor is prolonged to ensure the conversion rate of the monomers, so that the production efficiency is reduced, and the quality of the finally obtained hydroxyl acrylic resin is poorer. If the reaction temperature is too high, the pressure of a reaction system is higher, the reaction process is too violent, the heat exchange requirement on the continuous channel reactor is strict, the reaction is difficult to control, and the reaction temperature is too high, so that the branching condition of the resin is aggravated, gel is easy to generate, and the quality of the resin is influenced.

The residence time of the materials in the polymerization reaction unit 3 can be adjusted along with the reaction temperature, and the residence time adopted in the method is 1-20 min. If the retention time is too long, the generated hydroxy acrylic resin can continue to generate polymerization reaction at high temperature, so that the molecular chain of the resin is lengthened, the molecular weight of the resin is increased, and the viscosity of the finally obtained resin is increased, thereby influencing the use of the resin; if the residence time is too short, the monomer residue is too much, and the solid content of the resin is reduced.

In this application, monomer polymerization goes on and monomer polymerization process is exothermic process under higher temperature, and polymerization rate is faster under higher reaction temperature, and the heat that the reaction was given off is more, consequently can in time remove the reaction heat when providing the required temperature of reaction through reaction temperature control system 5. The reaction temperature control system 5 employed in this application controls at least one reaction temperature zone for the polymerization reaction unit 3.

In addition, since the reaction temperature of the polymerization reaction unit 3 is high, the temperature of the hydroxyl acrylic resin flowing out through the polymerization reaction unit is high, and if the resin is directly cooled by an external cooling system, energy cannot be fully utilized. The main components in the first mixed solution are monomer or monomer and solvent, the stability of the first mixed solution is not influenced by the rising temperature, the first mixed solution can be preheated to a higher temperature, the second mixed solution contains initiator, and if the preheating temperature of the initiator is higher, the initiator can be decomposed, so the preheating temperature of the second mixed solution is not high. Therefore, in an embodiment of the present application, the first material heat exchange system 6-1 is adopted to simultaneously achieve the first-stage temperature reduction of the hot hydroxyl acrylic resin and the preheating of the first mixed liquid, and the second material heat exchange system 6-2 is adopted to simultaneously achieve the second-stage temperature reduction of the hydroxyl acrylic resin after the first-stage temperature reduction and the preheating of the second mixed liquid, so as to achieve the comprehensive utilization of energy and achieve the effect of energy saving.

The first material heat exchange system 6-1 comprises a hot resin inlet, a first-stage cooled resin outlet, a first mixed liquid inlet and a preheated first mixed liquid outlet. The second material heat exchange system 6-2 comprises a first-stage cooled resin inlet, a second-stage cooled resin outlet, a second mixed liquid inlet and a preheated second mixed liquid outlet.

The material heat exchange system can adopt a dividing wall type heat exchanger, preferably a tubular heat exchanger. The inlet and outlet of the resin may be located at both ends of the tube side of the tube heat exchanger, and the inlet and outlet of the mixed liquor may be located at both ends of the shell side of the tube heat exchanger.

The hot hydroxyl acrylic resin flowing out of the polymerization reaction unit 3 firstly enters a first material heat exchange system 6-1 for primary cooling to about 70-100 ℃, and the first mixed solution is preheated to about 110-200 ℃ by the first material heat exchange system 6-1 in the process. And the hydroxyl acrylic resin subjected to the primary cooling enters a second material heat exchange system 6-2 to be subjected to secondary cooling, the temperature is reduced to about 55-75 ℃, and meanwhile, a second mixed solution is preheated to about 70-100 ℃ by the second material heat exchange system 6-2.

In this application, owing to adopt higher reaction temperature, if react under the ordinary pressure, the vaporization easily takes place for low boiling point material, causes the loss of material, material proportion unbalance, influences the quality of product, also can cause harm to environment and people's health, consequently this application can adopt backpressure adjusting device (not shown in the figure) to carry out backpressure control to the reaction system. A pressure regulating valve can be arranged on a connecting pipeline between a resin outlet and the receiving unit 4 after the second-stage cooling of the second material heat exchange system 6-2, the pressure of the reaction system and the material heat exchange system can be regulated and controlled by feeding back the pressure of the system in real time through a pressure sensor, and the pressure of the polymerization reaction unit 3 and the material heat exchange system can be controlled to be 1-5 MPa in the application.

The receiving unit 4 may comprise a receiving tank in communication with the tube side outlet of the second feed heat exchange system 6-2.

In the application, each system and unit in the continuous production device for producing the hydroxy acrylic resin can be connected with an automatic control system for automatic operation, so that the continuous automatic production of the hydroxy acrylic resin can be realized. In the application, besides the detection and control devices of flow, pressure and temperature, the continuous production device can also be provided with an overpressure safety interlocking system and an overtemperature safety interlocking system.

The overpressure safety interlock system includes a pressure sensor and a flow sensor disposed in the material delivery system 2. When the high pressure of the continuous conveying system 1 exceeds 6MPa and the low pressure is lower than 0.1MPa, the flow rate reaches 1.5 times of the flow rate value corresponding to the handling capacity of the continuous production device, and any one of 1/3 which is lower than the flow rate value corresponding to the handling capacity of the continuous production device occurs, the overpressure safety interlocking system executes emergency stop, sends out a protection signal, closes the feeding pump, performs safety protection on the continuous production device, and avoids serious loss caused by dangerous diffusion.

The over-temperature safety interlocking system comprises a temperature sensor arranged in the polymerization reaction unit 3, when the temperature in the reaction unit 4 exceeds 250 ℃, the over-temperature safety interlocking system can adjust the amount of a heat exchange medium provided by the reaction unit 4 through a regulating valve, execute emergency stop, send out a protection signal, close a feed pump, perform safety protection on a continuous production device, and avoid serious loss caused by dangerous diffusion.

In addition, the continuous production device can be set with four working modes, namely a production mode, a cleaning mode, a trial run mode and a shutdown mode, and can be controlled through remote operation, so that the safety of automation and production is greatly improved.

The concrete steps of one embodiment of the method for producing the hydroxyl acrylic resin by adopting the continuous production device can be as follows:

step 1: the monomer, the solvent and the initiator to be mixed are respectively fed into a mixer of the mixing unit 1 to be mixed in advance, and a first mixed solution containing the monomer and the solvent and a second mixed solution containing the solvent and the initiator are obtained.

Step 2: continuously conveying the first mixed solution and the second mixed solution to material heat exchange systems 6-1 and 6-2 through a material conveying system 2, preheating the mixed solution in the material heat exchange systems 6-1 and 6-2, then allowing the preheated mixed solution to enter a polymerization reaction unit 3, and performing rapid reaction at the temperature of 160-230 ℃ for 1-20 min to obtain hot hydroxyl acrylic resin;

and step 3: the hot hydroxyl acrylic resin flowing out of the polymerization reaction unit 3 enters the material heat exchange systems 6-1 and 6-2, is subjected to two-stage temperature reduction and then enters the receiving unit 4.

In the application, it is to be noted that all the materials for producing the hydroxyl acrylic resin can adopt industrial grade materials and can be obtained commercially; the various components of the continuous production apparatus employed, such as, for example, piping, valves, controllers, feed pumps, microchannel reactors, static tubular reactors, static mixers, dynamic tubular reactors, receiving tanks, etc., are commercially available from commercial sources, but the entire continuous production apparatus is not commercially available or known to those skilled in the art.

The present application will now be described in further detail with reference to the following comparative examples of batch tank production of hydroxyacrylic resins and the specific examples of the present application, which include but are not limited to the following examples, and any modifications made to the details and form of the technical solutions of the present application without departing from the meaning and scope of the present application are within the scope of the present application.

Comparative example:

the hydroxyacrylic resins were produced under the optimum kettle-type production conditions known to the inventors, as follows: adding 15 parts (by weight, the same below) of xylene and 20 parts of butyl acetate into a reaction kettle, preheating to 120 ℃, dropwise adding a mixed solution of 20.5 parts of styrene, 16.1 parts of methyl methacrylate, 17.6 parts of butyl acrylate, 26.3 parts of isooctyl methacrylate, 8 parts of hydroxypropyl acrylate, 11 parts of hydroxyethyl methacrylate, 0.5 part of acrylic acid and 1.5 parts of di-tert-amyl peroxide, maintaining the reaction temperature at 150 ℃, continuously dropwise adding a mixed solution of 5 parts of xylene and 1 part of di-tert-amyl peroxide within 6 hours, after 1 hour of dropwise adding, heating to 160 ℃, continuously preserving heat for 3 hours, cooling to 70 ℃ to obtain the hydroxyl acrylic resin, wherein the measured solid content of the resin is 59.5%, and the viscosity is 3400 cP.

In the industrial production process of the batch kettle type process, in order to realize the capacity of 5000 tons per year, two sets of 10 cubic meter reaction kettles need to be set, 450 batches are intermittently produced per year, the operation is complex, and the production efficiency is not high.

Example 1:

as shown in fig. 1, 18.43 parts of styrene, 14.58 parts of methyl acrylate, 5.23 parts of ethyl acrylate, 6.05 parts of isooctyl methacrylate, 4.6 parts of hydroxyethyl methacrylate, 4 parts of hydroxypropyl acrylate, 0.14 part of acrylic acid, 10 parts of xylene, and 5 parts of butyl acetate were introduced into the first mixer 11, and mixed uniformly to obtain a first mixed solution, and 2 parts of t-butylperoxycumene, 10 parts of xylene, and 20 parts of butyl acetate were introduced into the second mixer 1-2, and mixed uniformly to obtain a second mixed solution.

The first mixed solution is preheated to 163 ℃ by a first material heat exchange system 6-1, the second mixed solution is preheated to 92 ℃ by a second material system 6-2, the preheated first mixed solution and the preheated second mixed solution are continuously conveyed by a feed pump to enter a continuous channel reactor which is formed by sequentially connecting a micro-channel reactor and a static mixer in series, and are rapidly reacted for 1min under the conditions of 195 ℃ and 3.5MPa to obtain hot hydroxyl acrylic resin, and the hot hydroxyl acrylic resin sequentially enters the first material heat exchange system 6-1 (cooled to 98 ℃) and the second material heat exchange system 6-2, is cooled to 75 ℃ and then enters a receiving tank.

The obtained hydroxyl acrylic resin has a solid content of 55%, an acid value of 2mgKOH/g, a hydroxyl value of 70mgKOH/g and a viscosity of 2000 cP.

One set of continuous channel reactor with liquid holdup of 50L can reach 20000 tons of annual output, and compared with two sets of 10 cubic meters reaction kettles in the comparative example, the production efficiency is improved by 3 times, and 24 ten thousands of calories per hour are saved.

Example 2:

as shown in fig. 2, 21.85 parts of styrene, 14.88 parts of ethyl methacrylate, 7.31 parts of isooctyl acrylate, 9.78 parts of butyl methacrylate, 11.4 parts of hydroxypropyl acrylate, 14 parts of hydroxyethyl methacrylate, and 1.86 parts of methacrylic acid were introduced into the first mixer 1-1, and mixed uniformly to obtain a first mixed solution, 3 parts of di-tert-butyl peroxide and 15 parts of propylene glycol dimethyl ether were introduced into the second mixer 1-2, and mixed uniformly to obtain a second mixed solution, and 1 part of di-tert-butyl peroxide was introduced into the third mixer 1-3, and a third mixed solution was obtained.

The first mixed solution is preheated to 200 ℃ by a first material heat exchange system 6-1, the second mixed solution is preheated to 70 ℃ by a second material system 6-2, the preheated first mixed solution and the preheated second mixed solution are continuously conveyed by a feed pump, and enter a continuous channel reactor formed by sequentially connecting a microchannel reactor, a first static tubular reactor, a static mixer and a second static tubular reactor in series from a material inlet of the microchannel reactor, wherein the temperature of the microchannel reactor, the first static tubular reactor and the static mixer is controlled to be 180 ℃ by a reaction temperature control system 5, and the temperature of the second static tubular reactor is controlled to be 230 ℃ by the reaction temperature control system 5. The materials are quickly reacted for 2min under the conditions of 180 ℃ and 5MPa in the process of continuous flowing mixing in the continuous channel reactor, then the reaction materials and third mixed liquid entering the continuous channel reactor from a material inlet of the static mixer continuously react for 1min, and then quickly reacted for 3min under the conditions of 230 ℃ and 5MPa to obtain hot hydroxyl acrylic resin, and the hot hydroxyl acrylic resin sequentially enters a first material heat exchange system 6-1 (cooled to 72 ℃) and a second material heat exchange system 6-2, is cooled to 65 ℃ and then enters a receiving tank.

The obtained hydroxyl acrylic resin has the solid content of 85 percent, the acid value of 15mgKOH/g, the hydroxyl value of 135mgKOH/g and the viscosity of 5500 cP.

According to a set of continuous channel reactor with the liquid holdup of 180L in the example 2, the annual output can reach 13000 tons, and compared with two sets of 10 cubic meters of reaction kettles in the comparative example, the production efficiency is improved by 1.6 times, and the energy is saved by 15.5 ten thousand kilocalories per hour.

The solid content is measured according to GB/T1725-2007, the viscosity is measured by an NDJ-1 type rotary viscometer according to GB/T2794-2013, the acid value is measured according to GB/T2895-2008, and the hydroxyl value is measured according to GB/T12008.3-2009.

The application has the following beneficial effects:

1. the application provides a continuous production device of hydroxyl acrylic resin compares in current intermittent type cauldron formula production and has not only realized continuous automated production, obtain stable quality's hydroxyl acrylic resin, more showing and improving production efficiency, continuous automated production has saved the feeding and blowing process of intermittent type cauldron formula technology and because the poor quality of product or the unstable filtration process that adds before collecting the product in addition, operation procedure has been simplified, remote accurate control makes the security higher, can realize solid content for 50 ~ 90%'s hydroxyl acrylic resin's continuous production.

2. The application provides a continuous production device of hydroxyl acrylic resin has compared in current technology and has increased material heat transfer system, realizes preheating mixed liquid at the in-process of the hot hydroxyl acrylic resin cooling that obtains the reaction, has realized the comprehensive utilization of energy, compares in direct to the hydroxyl acrylic resin cooling and has reduced the waste to the energy.

While the foregoing is directed to the preferred embodiment of the present application, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the application.

Claims (10)

1. A continuous production device of hydroxyl acrylic resin is characterized in that,

the continuous production apparatus includes:

the mixing unit comprises a plurality of blenders capable of premixing materials, and comprises a material inlet and a mixed liquid outlet;

the material conveying system comprises a plurality of feeding pumps which provide power for the continuous conveying of materials, the material conveying system comprises a mixed liquid inlet and a mixed liquid outlet, and the mixed liquid inlet of the material conveying system is communicated with the mixed liquid outlet of the material mixing unit;

the polymerization reaction unit can receive the mixed materials and react to generate hydroxyl acrylic resin, the polymerization reaction unit comprises a mixed liquid inlet and a resin outlet, and the mixed liquid inlet of the polymerization reaction unit is communicated with the mixed liquid outlet of the material conveying system;

the receiving unit is used for receiving hydroxyl acrylic resin and comprises a resin inlet, and the resin inlet of the receiving unit is communicated with the resin outlet of the polymerization reaction unit; and

the heat exchange system comprises a material heat exchange system and a reaction temperature control system.

2. The continuous production apparatus according to claim 1,

the upper pressure limit of a feed pump of the material conveying system is not lower than 2 MPa.

3. The continuous production apparatus according to claim 1,

the polymerization reaction unit comprises a continuous channel reactor,

the continuous channel reactor comprises a micro-channel reactor and a tubular reactor,

the microchannel reactor has a mixing function,

the tubular reactor comprises one or more of a static mixer with a mixing unit in the lumen, a static tubular reactor without a mixing unit in the lumen, and a dynamic tubular reactor with moving parts in the lumen.

4. The continuous production apparatus according to claim 3,

the mixing unit comprises two mixed liquid outlets, and the two mixed liquid outlets are communicated with a micro-channel reactor or a static mixer or a dynamic tubular reactor at the front end of the continuous channel reactor.

5. The continuous production apparatus according to claim 3,

the mixing unit comprises three mixed liquid outlets,

the two mixed liquid outlets of the mixing unit are communicated with a micro-channel reactor or a static mixer or a dynamic tubular reactor which is positioned at the front end of the continuous channel reactor,

the other mixed liquid outlet of the mixing unit is communicated with a micro-channel reactor or a static mixer or a dynamic tubular reactor in the continuous channel reactor,

the resin outlet of the polymerization reaction unit is positioned on the tubular reactor at the rear end of the continuous channel reactor.

6. The continuous production apparatus according to claim 1,

the heat exchange system comprises a reaction temperature control system, and the polymerization reaction unit forms at least one temperature zone through the reaction temperature control system.

7. The continuous production apparatus according to claim 1,

the material heat exchange system can preheat mixed liquid after materials are mixed and can cool the hydroxy acrylic resin produced by the polymerization reaction unit,

the material heat exchange system comprises a first material heat exchange system and a second material heat exchange system,

the first material heat exchange system comprises a hot resin inlet, a first-stage cooled resin outlet, a first mixed liquid inlet and a preheated first mixed liquid outlet;

and the second material heat exchange system comprises a first-stage cooled resin inlet, a second-stage cooled resin outlet, a second mixed liquid inlet and a preheated second mixed liquid outlet.

8. The continuous production apparatus according to claim 7,

the continuous production device comprises a back pressure adjusting device,

the back pressure adjusting device comprises a pressure adjusting valve and a pressure sensor which are arranged between a second-stage cooled resin outlet of the second material heat exchange system and a resin inlet of the receiving unit,

the backpressure of the polymerization reaction unit and the backpressure of the heat exchange system are controlled to be 1-5 MPa.

9. The continuous production apparatus according to claim 1,

the continuous production plant comprises an overpressure safety interlock system comprising a pressure sensor and a flow sensor arranged in the material conveying system, and/or

The continuous production apparatus includes an over-temperature safety interlock system including a temperature sensor disposed in the polymerization reaction unit.

10. The continuous production apparatus according to claim 1,

the mixer in the mixing unit is a stirring kettle, and the heat exchange equipment of the heat exchange system is a dividing wall type heat exchanger.

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